Free Plant Breeding and Genetics MCQs with Answers

• A. Gramineae
• B. Solanaceae
• C. Cruciferae
• D. None of the above

Explanation: In grasses of the family Gramineae, self-incompatibility is commonly controlled by two loci, designated S and Z.

• A. Diallelic SL
• B. Ovarian SL
• C. Polyallelic SL
• D. Styler SL

Explanation: When incompatibility genes are expressed in the style or pistil tissue, the system is called stylar self-incompatibility.

• A. None of the above
• B. Gerstel (1950)
• C. East (1940)
• D. Koelreuter (1763)

Explanation: The term self-incompatibility is generally credited to East and Mangelsdorf, a name and date not included among the options.

• A. Inbreeding
• B. Out breeding
• C. Amphimixis
• D. All the above

Explanation: Mating between genetically or geographically distant individuals is called outbreeding, which introduces variation and generally increases…

• A. Male sterility
• B. Dichiny
• C. Herkogamy
• D. All the above

Explanation: Male sterility prevents self-pollination, dichogamy separates anther and stigma maturity, and herkogamy places them apart.

• A. Cleistogamy
• B. Hamogamy
• C. Chasmogamy
• D. All the above

Explanation: Cleistogamy is self-pollination and fertilization within a flower that remains closed or unopened.

• A. Homozy gosity
• B. Heterozy gosity
• C. Segregation
• D. none of the above

Explanation: Allogamy involves fertilization between genetically different plants, so it tends to maintain or increase heterozygosity in a population.

• A. Bruce and Keebel (1908)
• B. Mather (1953)
• C. Sewell Wright (1921)
• D. Shall and East (1920)

Explanation: Sewall Wright described major systems of mating, including random mating, inbreeding, and assortative or disassortative mating, in his…

• A. Centers of diversity
• B. Micro centers
• C. Gene sanctuaries
• D. Genetic diversity

Explanation: A center of diversity is a geographical region where a crop and its relatives show especially wide genetic variation.

• A. Active collection
• B. Indigenous collection
• C. Working collection
• D. Exotic collection

Explanation: Germplasm collected from and originating within its own country is called indigenous collection.

• A. Modern cultivars
• B. Advanced breeding materials
• C. All the above
• D. Land race

Explanation: A gene pool in crop breeding may include the genetic resources available for improvement, such as modern cultivars, advanced breeding…

• A. Obsolute cultivars
• B. Gene bank
• C. Ex-situ conservation
• D. In-situ conservation

Explanation: In-situ conservation keeps germplasm alive in its natural habitat, allowing populations to continue adapting there.

• A. CIP Peru
• B. Florida
• C. Columbia
• D. None of the above

Explanation: The International Potato Center, or CIP, in Peru maintains the major global potato germplasm collection.

• A. 200 years
• B. 150 years
• C. 100 years
• D. 1250 years

Explanation: Under suitable long-term gene-bank conditions, germplasm is commonly described in standard texts as being storable for about 100 years.

• A. China
• B. Mexico
• C. IRRI Philippines
• D. None of the above

Explanation: The International Rice Research Institute at Los Baños, Philippines, maintains the world’s major rice germplasm collection.

• A. 980
• B. 1080
• C. 1200
• D. 1100

Explanation: Older agricultural genetics references commonly report approximately 980 crop gene banks worldwide.

• A. Morgan
• B. Mather
• C. Shull and East
• D. None of the above

Explanation: Mather introduced the concept of disruptive selection, in which selection favours extreme phenotypes over intermediate ones.

• A. Barley
• B. wheat
• C. Maize
• D. None of the above

Explanation: Shull and East proposed the overdominance explanation of heterosis in maize in 1908.

• A. Grow put test
• B. Ageing test
• C. Test of genetic purity of seeds
• D. Tz test

Explanation: The tetrazolium (TZ) test stains living embryos, so stain intensity provides a rapid estimate of seed viability that generally correlates…

• A. Kittock and Law (1969)
• B. Woodstock (1976)
• C. Maguire (1962)
• D. Nicolls & Heu Decker (1968)

Explanation: Kittock and Law described estimating seed vigor from the intensity of staining produced in the tetrazolium test.